[Intel-devsys] irmx-80 diskettes
hjohnson at retrotechnology.com
Fri Aug 16 16:45:32 MDT 2019
Bill Beech's email of Aug 16 12:40 MDT, had an attached photo of one of
the physical paper labels on one 8-inch iRMX-80 diskette. The attachment
did not make the intel-devsys list archive of course. The text on the
label (I have reasons for posting this) says:
RMX/80 tm Real-Time Multitasker
Executive for iSBC 80/10
single density diskette
part no. 9500018-03 version 1.3
(C) Intel Corporation 1978
[copyright notice on Intel's software license, etc.]
If all of BIll's V1.3 diskettes are single density, then they aren't
M2FM double density. Many kinds of floppy controllers can read SD. And,
the disk capacity is only 250Kbytes or thereabouts; very manageable.
Bill, any of your CP/M 8-inch systems (if working) could read SD 8"
disks at the track/sector level. The CP/M program "DU" or "DUU" will let
you examine individual sectors, I'd bet on that.
A simple-enough disk copy program in ASM, could be modified to
read-a-track of sectors, write-to-serial. Jack's USB program, may
already do that, write-to-USB of course. Bill said recently, he bought
some of those serial-USB-drive dongles from the UK.
I just sent you, Bill, CPMUG disk #1 as ZIPped files, which contains an
ISIS dir program and an ISIS read-file program. You may be able to
"kermit" files from your CP/M system to a modern computer.
Possibly, some modified read-ISIS-disks-raw program under ISIS, can be
cajoled to read the iRMX disk on Bill's ISIS system, extract files.
I'm looking at the irmx-80 V2.4 files from Mark Ogden....no
disk-handling source files. Ditto, V4.0. No obvious help there, can't
run those iRMX binary programs!
page A-26, section A.6 Flexible Diskette formats
for iRMX I and iRMX II (8086 based), table A-1 says for 8-inch:
sector density sect/track
128 single 26
256 single 15
512 single 8
1024 single 4
256 double 26
512 double 15
1024 double 8
page A-1, section A-1 "Structure of a named volume"
(again - this is iRMX-86 documentation.) Describes at an absolute byte
number from 0, the format of named volumes. The concept is "fnodes", a
root directory, space for a bootstrap loader, and some volume labels, a
pool of fnodes (blocks of storage). There's hints of diskette methods
(the iRMX volume label is in sector 4 of a single density flexible
This gets busy fast.
My suggestion to Bill: just image the whole damn diskette, every sector.
It's only 256Kbytes total. Let other folks figure out how to peel off
the files from a saved image. With luck, Mark Ogden or someone, has a
irmx-86 (or -80) file extractor already in hand. Recovering the disk
image is the essential work, "only the wearer knows where the shoe
rubs". And recovering the bootstrap loader would be a good thing; I
don't know if the other irmx-80's have such a recovery.
Hope this helps.
On 8/16/2019 5:40 PM, Jack Mcmullen wrote:
> Hi Bill and all,
> The USB Imager/Creater is a direct SBC202 communicator. Was the only way
> on my side I could do an image. Understand your other hardware. Thought
> all of us had at least that basic configuration for 80/85 stuff. USB
> file movement tools goes thru ISIS.
Herbert R. Johnson, New Jersey in the USA
http://www.retrotechnology.com OR .net
preserve, recover, restore 1970's computing
email: hjohnson AT retrotechnology DOT com
or try later herbjohnson AT retrotechnology DOT info
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